chapter 1

Introduction1.1 INTRODUCTIONCloud computing is an architecture for providing computing services via the internet on demand and payper use access to a pool of shared resources namely networks, storage, servers, services andapplications, without physically acquiring them. So it saves managing cost and time for organizations.Many industries, such as banking, healthcare and education are moving towards there cloud due to theefficiency of services provided by the pay-per-use pattern based on the resources such as processingpower used, transactions carried out, bandwidth consumed, data transferred, or storage space occupiedetc.1.2 MEANING AND DEFINITION OF CLOUD COMPUTINGCloud computing is a computing paradigm, where a large pool of systems are connected in private orpublic networks, to provide dynamically scalable infrastructure for application hosting, content storage anddelivery is reduced significantly.Cloud computing has become the new buzz word given largely by marketing and service offerings frombig corporate players like Google, IBM and Amazon. Cloud computing is the next stage in evolutin of theinternet."Cloud computing is a specialized form of distributed computing that introduces utilization models forremotely provisioning scalable and measured resources."Cloud computing is a completely internet dependent technology7 where client data is stored and maintainin the data center of a cloud provider like Google, Amazon, Salesforce.com and Microsoft etc. Limitedcontrol over the data may incur various security issues and threats which include data leakage, insecureinterface, sharing of resources. Data availability and inside attacks. There are various researchchallenges also there for adopting cloud computing such as well managed service level agreement (SLA),privacy, interoperability and reliability.Defines cloud computing as:A pool of abstracted, highly scalable, and managed compute infrastructure capable of hosting endcustomer applications and billed by consumption.Forrester Research provided its own definition of cloud computing as:A standardized IT capability (services, software, or infrastructure) delivered via Internet technologies in apay-per-use, self-service way.Cloud computing is the delivery of computing services over the Internet. Cloud services allow individualsand businesses to use software and hardware that are managed by third parties at remote locations.Example of cloud services include online file storage, social networking sites, webmail and onlinebusiness applications. The cloud computing model allows access to information and computer resourcesfrom anywhere that a network connection is available. Cloud computing provides a shared pool ofresources, including data storage space, networks, computer processing power and specialized corporateand user applications.Cloud computing is a model for enabling convenient, on-demand network access to a shared pool ofconfigurable computing resources (e.g., networks, servers, storage, applications and services) that canbe rapidly provisioned and released with minimal management effort or service provider interaction. ThisCloud model promotes availability and is composed of five essential characteristics, three service modelsand four deployment model.Institute of Standards and technology (NIST)Cloud computing is an architecture for providing computer service via internet on demand and pay pertuse access to a pool of shared resources namely networks, storage, servers, services and applications,

without physically acquiring them.

1.2 HISTORICAL DEVELOPMENTThe term cloud is used as a representation of the Internet and other communications systems as well asan abstraction of the underlying infrastructures involved. What we now commonly refer to as cloudcomputing is the result of an evolution of the widespread adoption of virtualization, service-orientedarchitecture, autonomic and utility computing.The idea of computing in a cloud traces back to the origins of utility computing, a concept that computerscientist John McCarthy publicly proposed in 1961:If computers of the kind I have advocated become the computers of the future, then computing maysomeday be organized as a public utility just as the telephone system is a public utility. The computerutility could become the basis of a new and important industry. In 1969, Leonard Klein rock, a chiefscientist of the Advanced Research Projects Agency Network or ARPANET project that seeded theInternet, stated: As of now, computer networks are still in their infancy, but as they grow up and becomesophisticated, we will probably see the spread of computer utilitiesThe general public has been leveraging forms of Internet based computer utilities sincethe mid-1990s through various incarnations of search engines (Yahoo!, Google), E-MAIL SERVICES(Hotmail, Gmail), open publishing platforms (Myspace, Facebook, YouTube), and other types of socialmedia (Twitter, LinkedIn).